working

sw.js

@@ -0,0 +1,50 @@
+const CACHE_NAME = 'nexus-timer-cache-v3'; // Increment cache version
+const URLS_TO_CACHE = [
+    'index.html',
+    'style.css',
+    'script.js',
+    'manifest.json',
+    'assets/default-avatar.svg',
+    // MP3 files removed as they are no longer used
+    'assets/icon-192x192.png',
+    'assets/icon-512x512.png'
+];
+
+self.addEventListener('install', event => {
+    event.waitUntil(
+        caches.open(CACHE_NAME)
+            .then(cache => {
+                console.log('Opened cache');
+                return cache.addAll(URLS_TO_CACHE);
+            })
+    );
+});
+
+self.addEventListener('fetch', event => {
+    event.respondWith(
+        caches.match(event.request)
+            .then(response => {
+                if (response) {
+                    return response;
+                }
+                return fetch(event.request);
+            }
+        )
+    );
+});
+
+self.addEventListener('activate', event => {
+    const cacheWhitelist = [CACHE_NAME];
+    event.waitUntil(
+        caches.keys().then(cacheNames => {
+            return Promise.all(
+                cacheNames.map(cacheName => {
+                    if (cacheWhitelist.indexOf(cacheName) === -1) {
+                        console.log('Deleting old cache:', cacheName);
+                        return caches.delete(cacheName);
+                    }
+                })
+            );
+        })
+    );
+});